1. Field of the Invention
This invention relates to an optical beam steering device, and in particular to a device for steering high power light beams.
2. Discussion of Prior Art
Optical beam steering devices are well-known in the prior art. Typical electro-mechanical devices involve a moving mirror employed to deflect a light beam. This suffers from the disadvantage that the energy required to rotate such a mirror is proportional to the fifth power of the mirror diameter (D.sup.5). High power light beams require large diameter steering mirrors so that the power density at the mirror surface is less than a damage threshold. In consequence, high power beam steering requires a bulky and expensive moving mirror assembly.
Acousto-optical and electro-optical beam steering devices are also known in the prior art. The former comprises a piezo-electric block in which acoustic waves interact with a light beam to produce steering. The latter comprises an electro-optical waveguide array which is an optical analogue of a radar phased array. Beam steering is achieved by varying the bias voltage on (and thereby the phase change induced by) individual waveguides. However, the power handling capacity of each of these devices is severely restricted. It is orders of magnitude below that required to accommodate high power laser beams.